The Laboratory of Human Reproduction and Reproductive Biology is a multidisciplinary center for research and training in reproduction. The NIH center grant supports core facilities and services which are an integral part of the research process and facilitate the conduct of the Laboratory's activities. The core services include: electron microscopy, histology, photography, peptide analysis and synthesis, radioimmunoassay, biometrics, animal facility, glass washing, machine shop, material handling, administration, and a seminar program. The research activities and projects which depend upon these core services include: 1) Biochemical events surrounding spermatogenesis involving histone and nonhistone chromosomal protein synthesis and transformation, 2) ultrastructural studies of oocyte, granulosa cell, blastocyst and spermatocytes with emphasis on cell junctions, membrane structure, receptors and function, 3) processing of ribosomes during oogenesis, and control of meiotic process, 4) steroid and protein hormone receptors in target tissues, 5) electronprobe analysis of elemental composition of cells and fluids of reproductive system (e.g., blastocyst and oviductal fluid), 6) synthetic and natural reproductive steroid biosynthesis and metabolism, 7) isolation, synthesis and function of hypothalamic polypeptides, 8) steroid hormone and neurotransmitter metabolism binding and function in the brain, 9) molecular aspects of androgen to estrogen conversion, 10) control of early aspects of fertilization and implantation as well as endocrine control of pregnancy length and parturition, 11) ovarian, testicular, and placental steroidogenesis and 12) mechanism of hormone action. A developmental program is planned for the application of mass spectroscopy to reproduction population research.